Heat sensitivity depends on the ink set as well the paper. And the particular model of printer comes into play, too.
As a general rule, digital reproductions should not be dry mounted, because we generally do not know enough about their composition. If you can determine the ink set, paper, and printer model, then you can refer to charts for specific limitations. Start with
www.wilhelm-research.com.
If you aren't concerned about preservation and decide to 'wing it', then use as low a temperature as possible, and for as short a duration as possible.
Not all damage from heat mounting is noticeable right away. Degradation of the inks or paper coatings might show up later as color shift or accelerated fading.
Of coursed, if these are collectible artworks, then no permanent mount would be acceptable, even if it could be accomplished without obvious harm. The first rule of preservation mounting is that it must be completely reversible with non-invasive methods. That eliminates dry mounting, wet mounting, spray mounting.
In that case, edge mounts are often best.